Armageddon on Infinite AU's
by Inkblot the Author
Summary: Errortale, Underfell, Underswap, Reapertale, Horrortale, Underfresh, Aftertale, Outertale...all names. All things have a beginning and an end, as do these. Something is happening in the multiverse, and Error is up front and center. A cataclysm, an event is near. The end or beginning of all. Reality is in danger. All will have to come together, or be doomed to erasure.
1. Prologue

**Hello there! My name is Inkblot the Author. I've written only one fanfiction before, which I thought was absolute trash. So, I'm fairly new to this whole story-writing thing. But, I will do my best on this story, and do my absolute darnedest to make it a fun and interesting experience for any and all who read this! The little preface is a little bit of background information about the whole "Alternate Universe" thing, if anyone who reads this doesn't know. Also, side note, although the AU Sanses in this story will be the same, their backstories may be a little different to fit the story I'm creating. So please, don't get angry with me if everything I write isn't 100% fitting to the original author's origin story for each of these characters. So, without further ado, I present to all of you,**

 ** _Armageddon on Infinite AU's!_**

 _It was the same as it had been so many times before. A human child imprisoned, and all of the inhabitants of the world destroyed. A cavern hidden under the mighty Mt. Ebott, once full of the curious and interesting Monster race, now devoid of life entirely. For this was the work of the monster known as Error Sans. This creature knew only how to destroy. A destroyer of worlds and universes, so he was called. Once a normal inhabitant his world, he was changed by an unknown force. This force changed his abilities, his personality, and his mind. Error, in a fit of psychopathic rage, destroyed all of the monsters in his home universe, and set out to do the same to all of the inhabitants of reality, known as the multiverse. Travelling through the multiverse, he destroyed any and all he considered impure. For all but one of these many universes was considered an anomaly to Error, one which he sought to correct. These worlds were known as "AU"'s, alternate universes. These worlds were similar to, yet different than, the main universe of the multiverse, known as "Undertale". And so, the creature known as Error Sans wreaked havoc throughout the universe, leaving unspoken numbers of dead in his wake. Only one could challenge his power. Only one individual could reverse the effects of the monster's path of terror. The creature known as Ink Sans._

 _Ink Sans was a creature of immense power. He had obtained the power of creation, through his paintbrush which he used to create new worlds, new life, and new AU's. This Sans was the polar opposite the monster, Error. He was happy, carefree, bright, and a shining beacon of hope in the dark path Error created as he traversed the vast multiverse. The duo had done battle countless times during each other's lifetimes, but each time, it had ended prematurely, or it had ended in a tie, neither able to triumph over the other. It was maddening to the psychopathic Error Sans, who desired only to destroy all those who were not of the original, "pure", Undertale universe. So the cycle continued, through maddening lengths of the time, always ending the same way, not a single thing changing after each battle._

 _Then, something did change. A seemingly unaltered wave across the multitudinous universes and worlds. A single message. One that seemed to hold no significance, but would be in the minds of all. Seven simple words. Words that would change the fate of all that resided in the massive multiverse. Though, these words of immense power did not reach the mind of but one individual. One creature, a destroyer, a monster, a murderer, a psychopath. The words that spanned the multiverse did not reach the mind of one individual alone. And the individual was the monster known as Error Sans. All others knew the words, none knew the significance, and only one was left out of the message that had spanned all of reality. All variations of all the creatures that live in the cavern under Mt. Ebott, they all knew the words-all but the one who would influence them most. So begins the end. The beginning. The change. The stirring. The greatest cataclysm the multiverse had ever seen, and the most beautiful sight that reality would bear witness to. And it all started with words. Seven words. Words that would influence the event. The event that would change the multiverse forever, and it would start with the words, the encounter, the fated battle, the sadness, and the final cataclysm. The words. The words. The words. The journey begins now. All will have a say and a chance to change the fate of the multiverse, even the most unlikely. The fates of Error Sans and Ink Sans will be decided, as will the fate of all who have lived under the mountain known as Mt. Ebott, and all who will ever live in the vast existence known as the multiverse._

 ** _It Begins._**


	2. The Encounter

Another one destroyed. It was all the same. Another species eradicated. It was nothing new. Error Sans had yet again destroyed the Monsters, the species which he once called his own. Toriel, Undyne, Alphys, Asgore, Mettaton, and even Papyrus. All of the monsters considered unimportant. All gone, with no one to bring them back, for the fallen child had been killed as well. Error stepped among the ashes of the great king Asgore, having overpowered his once mighty trident and fire attacks. There was only one monster left to destroy, before the world was destroyed once more, for this monster was the reason he had come and eradicated them all. This monster had always been the most powerful among them all, but in this world, even more so. The world's Sans was irregular, possessing more power than normal, even among the vast range of Sanses that inhabited the multiverse. But something stopped the monster. It was not known why at the time.

Error was, at the time, standing in the hallway known as the Judgement Hall. Orange-yellow light filled the corridor, casting a long and distinct shadow across the floor and beautifully sculpted pillars. It was as if he had been struck from behind. Error Sans turned around. He was a strange thing to behold. He was a skeleton, with pure black bones, a rounded head, eye sockets, and a large smile. He was rather wide and short in stature, but nonetheless threatening. He wore a dark jacket, a red undershirt, and wore black shorts. With a sickly yellow hue to his teeth and a red color to his eye sockets, he truly looked insane. But his eyes-they were truly what made him appear to be a psychopath. One eye yellow, blue, and black, disordered and strange, the other a single pale white dot, a pinprick. White, computer-like lettering floated around him indefinitely, spelling out the words "ERROR". A strange being, this was. A horrifying one, and a terrifying thing.

Error spun around, and inspected the area behind him. He wished to kill the Sans of this universe, to completely purge and "purify" the world. Yet he had other business to attend to, business that concerned things much greater than one world. As much as it hurt him, he had a job to attend to. Using his magic, Error created a portal in front of him that was purely white. Looking rather like a glitch in the world, the portal looked uneven and consisted of many white squares and cubes around the border. Once again checking behind him to ensure no one was there, he smirked, displaying his yellow teeth.

"You can be sure that I'll be coming back for you, Abomination #47," Error said, his distorted and glitched voice echoing throughout the hallway.

Looking around one last time, he stepped through the portal, disappearing from the world, the portal collapsing in on itself as he stepped through. Then there was silence. Almost as soon as Error had left, another portal had formed in the Judgement Hall. This was not the same portal that the monster had just left in. This multiversal doorway seemed to be bordered by and composed of many colors of paint. As it rotated, it flung paint of all of the colors of the rainbow around the corridor, ruining its flawless look. Through the portal stepped another individual, of whom had the same body size and basic look as Error Sans. But the similarities stopped there. This individual was also a skeleton, yet it seemed to be bright and pure. It donned a long, brown scarf, a blue coat was tied around its waist, and it wore brown and yellow sneakers. The most distinctive trait of this Sans, however, was his massive paintbrush behind his back. It was perpetually dripping different colors of paint, and was about 2/3 the size of his own body. One of his eyes was a yellow star, and he also wore a band of leather across his body containing different colored bottles of paint.

As the portal collapsed in on itself, as Error's did, the new Sans looked around. He walked across the corridor, looking around, searching for signs of life. As he reached the end, he could tell he was too late. Before him lay a pile of white dust, the only evidence that a monster had ever existed after it had died. Beside it lay a huge red trident, a spoil of a battle and the chosen weapon of Asgore, king of the monsters. He reached down and ran his hand across the surface of the trident, muttering to himself.

"Come on, Error...I had real hope for this one." He sighed. "Can't you just leave _one_ alone for once? This one was going to be super cool…"

" _You!"_

The voice rang out harshly against the stillness of the Judgement Hall. Startled, the Sans spun around, ready to confront whatever was in the corridor with him. The voice had sounded harsh and angry, and he was ready to fight whatever it was…though there should have been nothing there. The Sans knew what Error Sans was capable of, and he never left any monsters in an AU alive. This was certainly not normal.

Standing at the opposite end of the hall stood another figure who looked just like the Sans, though different in many ways. He was also a skeleton, but wore a white shirt. He wore two orange gloves with black hearts on them, and wore grey pants. On his face were to dark streaks running down from his eye sockets, the left one containing a glowing orange eye. He looked furious, and in search of blood. Or dust, in the case of monsterkind.

"You monster…" he said with a pained expression on his face. "How could you kill them all…they were _innocent._ You even killed—"He paused. "You even killed _Papyrus!"_ At that, his left eye grew a brighter orange, and he assumed a fighting stance.

"Hold on, hold on!" The other Sans exclaimed quickly, not wanting a fight. "I'm not the one who killed everyone. The one that did that is named Error Sans," he explained. "My name is Ink Sans. I make worlds—I don't destroy them. What's your name?"

The other Sans didn't say a word. He still was prepared for battle.

"Why should I believe you? I saw you kill everyone. One that looked like me," he proclaimed loudly. "But I _will_ tell you my name, so that you know who will be the one to finally take you down." He tensed up. "My name is Delta, and…" suddenly, his voice seemed to layer, two voices, his and seemingly a child's, coming out of his mouth at once. " _We will make you pay for what you did!"_

With that, Delta sprinted forward at immense speeds, leaping into the air and bringing his orange-gloved fist down so that it appeared to be simply an orange blur coming at Ink. He managed to use his magic abilities to teleport away from the impact zone, but it still sent shockwaves rippling through the air and ground, throwing him off his feet even from the safe distance away. Ink looked back, and saw Delta's fist had sunken into the hard floor of the Judgement hall, with cracks spreading out from the impact zone.

"Well then," Ink breathed in surprise. "This seems to be slightly…irregular."

Delta managed to pull his hand out of the floor, and his left eye seemed to glow even brighter, now forming a see-through fire coming from his pupil. He threw himself at Ink once more, throwing dozens of punches per second, with Ink simply teleporting further and further away as Delta failed at landing a single punch. Crossing the Judgement Hall took nearly an instant, and, when they reached the wall, Ink leapt into the air. Not realizing they had reached the end of the corridor, Delta slammed himself into the wall at full speed. Landing gracefully a few meters away from the wall, Ink tilted his head to the side.

"You know, I may not have gotten a doctorate from some fancy university, but I'm pretty sure it's not very healthy to run into walls," he said sarcastically.

" _You shut up!"_ came the reply from Delta as he broke himself away from inside the wall and hurled a barrage of orange-hued bones at Ink, conjured using his magic.

Ink, quick as a flash, grabbed the massive brush from behind his back and swiped it in front of him. A large stroke of paint suddenly appeared in mid-air, which blocked the bones from striking him.

Looking up from his brush, Ink tried making peace. "Come on. If I was really the one who killed everyone, why would I even deny it? Use your head!" He said, tapping a bony finger to his skull. "Plus, I haven't even attempted fighting back. Why do you think that is?"

 _"_ Because you're a murdering coward!" Delta shot back, as he summoned two large dragon skulls in front of him.

Known as Gaster Blasters, these devices were deadly. The Gaster Blasters opened, and out of them came a blast of destructive magical energy, headed straight at Ink. Narrowing his eyes, he grabbed his brush with two hands, and twirled it in front of him at incredible speeds. This created a protective circle shield of ink, stopping the energy blasts in their metaphorical tracks. Looking up over the circle, his eyes widened as he saw Delta's enraged face for an instant before he sent an energized, glowing leg into Ink's protective barrier, the force from the kick travelling through the barrier, shattering it and flinging Ink backwards across the corridor. Managing to right himself in the air, Ink skidded across the floor, his gloves heating up immensely from the friction. Ink looked up, the yellow star in his eye flaring. He was annoyed now.

"Alright…not cool." Ink announced, an ounce of malice thrown into the words. "But clever, I'll give you that."

Delta gave him a humorless smile. "I told you I would make you pay, and you humiliating me earlier won't help the amount of pain you're going to receive," He said malevolently.

Ink sighed, shaking his head and gripping his brush tightly in both hands. "I didn't want to have to do this, but your hard-headedness has left me no choice." He looked up at Delta. "No one's ever gotten out of this. So don't even try."

Delta eyes narrowed, and he smirked. "What're you even—"

He didn't finish his sentence. Suddenly, Ink shot the bristles of his brush towards Delta, and circled it around and around, spewing a cylindrical blue substance that began rapidly wrapping itself around Delta.

"Hey! What the he—"he began saying, before getting his mouth covered up by the blue substance.

Soon enough, his entire body was wrapped in blue, leaving only his eyes to the exposed air.

"Hah! You look ridiculous," Ink smiled. "But this is what happens when you don't cooperate and believe that I didn't kill everyone." He narrowed his eyes. "Because that is _not_ who I am. I create worlds, and I create life. The one who destroyed your world is known as Error." He turned away, and began talking matter-of-factly, as if talking to a student. "Now, I'm going to take you to somewhere where people like you are safe. We call it the Omega—"

At that moment, Delta chose to strike. His orange eye glowing brighter than it ever had before, the then-blue bonds began to glow with an orange hue, and glowed brighter and brighter until they cracked and shattered, and he fell to the ground. Ink was dumbfounded.

"How—how did you _possibly—"_ he stuttered.

Delta smirked. "Help from a friend," he replied smartly.

Then, his orange eye flashing, Delta summoned a ring of large Gaster Blasters from which Ink couldn't escape from. His eyes widening in recognition, Ink wildly swung his brush around, creating a protective sphere of ink around himself. Ready for the blast at any moment, Ink braced himself for impact.

But the blast never came. Instead, Ink heard the Gaster Blasters being dissolved, and silence. Waiting a moment, Ink let down the sphere of ink around him. Looking around him, he saw Delta with a smile on his face.

"Wh—What?" Ink asked questioningly. "Why did you stop?"

"Simple," Delta replied. "If you were really the one who had killed everyone, you would've killed me on the spot. You wouldn't have protected yourself from the blast with a shield, you simply would've stabbed me through the stomach with your brush," he said simply.

"So…that last attack was a test?" Ink asked.

Delta nodded. "So…what you were saying was true. Someone else, named Error Sans, was the one who killed everyone…who killed Papyrus," Delta reasoned with a hint of malice in his voice.

Ink nodded. "Right. He's also destroyed countless other worlds. He thinks all AU's, or Alternate Universes—which is what we are—are impure." He looked away. "He's killed so many, and I've tried to stop him so many times…yet I'm never strong enough."

"Wow…so this guy must be pretty intense. Because…" Delta smirked. "I could tell you weren't trying your hardest against me. Not by a long shot."

"So…you noticed," Ink replied. "I could say the same for you. But right now, we need to get out of here. Error is bound to come back, so we need to leave this world."

Delta narrowed his eyes. "Leave this world? How? Where are we going?"

"Oh…yeah, that." Ink smiled kindly. "We're going to a good place. A place for refugees like yourself, survivors of so-called "genocide" universes." Ink waved his hand at Delta, gesturing him to join him at his side. "Come on. Let's go…to the Omega Timeline."

Summoning a swirling portal composed of ink of all the colors of the rainbow, Ink gestured for Delta to enter first. Stepping into the portal, Delta left his world…the last time he would ever step foot in it. Looking around one last time at the Judgement Hall, Ink stepped through the portal of ink, collapsing it on itself, leaving the world barren.

This world truly was barren. The Ruins, Snowdin, Waterfall, Hotland, the Core, the Kingdom. Devoid of life. Full of white dust. The future of all of its inhabitants destroyed, never again to be revived. Another one destroyed. It was all the same.


	3. The Threat

As Delta stepped through the swirling, multicolored ink portal, he couldn't believe his eyes. A massive expanse of white space was laid out before him, extending in every direction as far as the eye could see. But that wasn't what had caught his eye. In every direction, there were hundreds, if not thousands of people. Most of them were milling around, talking in groups, looking like the most bizarre people Delta had ever seen. Many of them were versions of himself, some with glasses, some looking like demons, some multicolored, some wearing fedoras. But there were others as well. There were dozens of different versions of Alphys, Undyne, Asgore, Mettaton, even a few versions of Frisk. But what had caught his eye wasn't any of these. What caught his eye was the many variations of Papyrus. They were as diverse as the many versions of himself, but he couldn't help feeling astonished, tearful, and joyous at the same time. Then, out of the crowd, a child walked up the Delta.

The child was very small, yet Delta couldn't help feeling intimidated by the small human. They had large, empty, dark eyes, wore a loose fitting gray sweater and black shorts, and had a bob haircut. They simply stared and smiled at Delta. Ink, having just walked through the portal, reached both of arms out, as if expecting a hug from the child.

"Core!" Ink exclaimed happily, arms still stretched. "It's good to see you again. How's life? How's the timeline, how's the wife and kids?" He added jokingly.

The child didn't respond to his outstretched arms. Instead, they responded in a quiet, soft, monotone voice, "the Omega Timeline has been fairing as well as it always has been Ink." They turned to Delta. "Who is this you've brought with you? A refugee, I presume?"

"Spot on!" Ink said. "Core, this is Delta. He's come from a post-genocide timeline." Gesturing to the child, Ink then spoke to Delta. "This is Core Frisk. They're the one that runs this whole shebang. Say hi!" He exclaimed.

Delta looked back nervously to the child. "Um…what's up?" He said as he waved at Core.

They simply tilted their head and regarded Delta from his shoes to the top of his head. "You're different. You're not like the other Sanses that live here," they said in a quiet voice. "There is more than one consciousness inhabiting your body. I know they're there." Core gave him a ghostly smile. "Tell Ink how you've acquired so much power. I suspect he would be interested.

Ink looked at Delta. "Yeah, that _is_ true…how have you gotten so powerful?" He said questioningly.

Delta looked down at the pure white surface of the floor. "Well, I guess there's no point in hiding it anymore." He looked up at them. "After Error killed—"he faltered. "Killed Papyrus…I broke into King Asgore's castle and absorbed the human soul of justice." He looked at the shocked expression on Ink's face, and spoke quickly. "The only reason I did it was to try and stop Error. He had killed everyone so…easily. I knew there was no way I could've face him on my own."

Ink paused, and nodded slowly. "It's true. Pretty much no one can stand up to Error, including me. And the ones who _can…_ " he glanced at Core, who looked back, acknowledging his reference. "Won't. They're too lazy."

Delta looked between them, wide-eyed. "Who? Who would do that? Are they here, in the Omega Timeline? Why haven't we forced them to help?" He cried.

Ink sighed. "We haven't been able to get his help because—well, he's already decided he won't…amongst himself." Delta simply looked at him, face blank. "Look—"Ink said, exasperated, and stopped himself before saying something rash. "Look, you just survived the eradication of your entire species, and your universe," Ink reasoned. "What you should be focused on right now is getting to know everyone here. They're just like you. Socialize a little. I'll talk to you later, okay?" And with that, Ink turned away, side by side with Core, as they went off to talk about other things.

Slightly suspicious of this, but not willing to eavesdrop, Delta decided to take Ink's advice. Turning back to the massive crowd of inhabitants of the Omega Timeline, he waded through the crowd, looking for someone interesting to talk to. A few feet away, he spotted a small group of Sanses and a Papyrus, talking among themselves. Interested, Delta got a little closer, hoping to listen in on their conversation. There were a few different versions of himself in the group, which Delta would never get over. One of them had blue eyes, a blue scarf, blue shoes, and a battle body much like Papyrus's. Another one of them looked intimidating, with a glowing red eye, spiked teeth, a black coat, and a red undershirt. He seemed to be in an indefinite bad mood. The last Sans in the group was definitely the strangest—he wore the same body armor, cape, and crown that Asgore had worn, but smaller robes that were blue.

The Papyrus in the group looked and acted very much like a Sans. Wearing an orange jacket, dark pants, and smoking a cigarette, he didn't look like much. Still, Delta felt a pang of sadness when he laid eyes on him.

The Papyrus was the first to notice Delta, and called him over, saying, "hey, you! Orange-gloves! Come over here!" When Delta shuffled over, Papyrus looked him over. "Hm… don't think I've seen you around here before. How 'bout'cha tell us your name?"

Looking at the faces around him, Delta spoke rather softly. "I'm, uh, I'm Delta. Error Sans…" that name got some reaction from the group. "Error Sans destroyed my universe. I guess this 'Omega Timeline' is meant for people like me?"

The intimidating Sans spoke up. "Yup, that's right. Nice to meet'cha, people around here call me Edge…for some reason. I never understood it." He nodded his head in the blue Sans' direction. "That there is Blue. Or Blueberry. Doesn't really matter." Blueberry waved at Delta enthusiastically. "That there," he said, gesturing at the Sans in the cloak, "is Shift." He looked up from the floor, somber-eyed, and slowly nodded at Delta. "And that over there…" Edge pointed at Papyrus. "We just call him Papyrus.

Papyrus smirked. "Can't improve on perfection, I guess." He took the cigarette out of his mouth, held it at his side, and looked at Delta. "So, what's your story? Why do you look so…" he gestured at his body nonchalantly. "Weird? For lack of a better term."

Delta looked down at himself. "Well, after my Papyrus was…killed by Error, I broke into King Asgore's castle." Shift looked up at Delta. "I absorbed the Bravery soul, in hopes of being able to stop him. But, I never got the chance to try." He looked up at the group. "So, who exactly _is_ this Error guy? Was the world of everyone here destroyed by him" He asked in an interrogating tone.

"Yeah, most of the universes of the people here have been destroyed by Error," Papyrus said, speaking first. "My world was also eradicated by the bastard. But…something different happened for us." Blue shifted his feet, looking uncomfortable, and Papyrus looked at him. "Error…took Sans, my bro, into the anti-void, his home. I'm not sure what happened in there, but one day, he showed up here." Papyrus clenched one of his fists, his left eye glowing a soft shade of orange. "But, if I know one thing, I know this. If Error shows one toe in here, _ever,_ he'll regret he was ever born." His eye returned to normal, and he stuck his hands in his pockets. "But that's not today. For now, we're here, living safely, away from that monster."

Delta nodded slowly. Then, remembering something he wanted to ask them, suddenly spoke again. "Oh! By the way, I wanted to ask you something real quickly." Papyrus, looking confused, agreed. "Alright, this is going to sound really weird, but…" he looked around the group. "Have you heard seven words in your mind?"

Leaving Delta behind, Ink walked alongside Core. Most of the inhabitants of the Omega Timeline cleared a path for them to walk easily, and gradually, the crowd of refugees thinned until Core and Ink were a fair distance away from the massive crowd. Ink then noticed just how small and fragile Core really looked. They were just about ¾ the height of Ink himself, and just a child. But a deep sadness still lingered about them. Core was an omnipresent being, able to traverse all possible timelines and universes at any time they chose. Ink was always intimidated by this small child, and rightfully so. Though they weren't powerful in the most common form of the word, they were powerful in the sense that they were everywhere. Their eyes were so large compared to their head, so empty, dark, and sad. Though, being thrown into the Core by your best friend and scattering across the multiverse, gaining omnipresence, will do that kind of a thing to a person.

Core looked up at him. "Ink, I've got some disturbing news. I haven't told anyone else here yet, as I don't want to stir up trouble and fear. Do you want to hear it?" Fearing for the worst but hoping for the best, Ink nodded. "Alright. There has been a notable increase in the number of worlds being destroyed across the multiverse. I believe Error is trying to get our attention. That, or he has recruited another in his desire to obliterate every AU."

Ink was incredulous. "Wait a minute, so, you're thinking that Error might have an…ally? Who could possibly be crazy enough to help that psycho?" He said, unbelieving.

"I'm simply telling you what has been happening," Core responded, voice impossible soft and timid. "But, there is another matter I want to discuss with you. Have you heard of seven words in your mind?" Core asked.

Ink's eyes widened. He hadn't really given any thought to it, but now that Core had mentioned it, it became impossibly obvious. "Yeah, I…I have been hearing seven words in my head, but…I've forgotten what they are. I know for certain that there were seven." Confused, Ink questioned Core. "Do you know what's going on here?"

Core shook their head. "No, I don't. However, I do know what words have been repeated. And yes, Ink, they've been repeated. Over and over, in the minds of every creature in the multiverse." Core tilted their head. "The only reason I've been able to hear what is being said is because I can be everywhere at one—I have received the message for what might as well be an infinite amount of times." They shook their head. "And even for what I can do, and what I am…even I don't know what significance they have."

Ink questioned Core further. "What words? What are the seven words? I need to know."

Core frowned. "Alright, but these words are incomprehensibly important. More important and significant to the fate of the multiverse than you can fully understand," Core explained. "You can't tell anyone else these words, no matter what. Do you understand, Ink?"

He nodded. "I understand, I won't tell anyone else."

Core closed their eyes for a moment, then opened them again. "Alright. The seven words are—"

They never got the chance to tell Ink. Suddenly, Core's eyes opened impossibly wide. "NO!" They cried, mouth opening.

Ink jumped, never hearing Core's voice never go above the volume of soft speaking. "What? What's happening what's wrong?" Ink questioned frantically. "Is it Error?"

Core nodded. "No, no, no, Error, you fool! Error is attempting to infiltrate Underfell, one of the core worlds of the multiverse. If it falls, which it undoubtedly will, if left alone for long enough, Error will have direct access to all of the other core universes." Core explained quickly. Ink tried to understand through how fast they were talking, and began to understand the crisis. "If Error gets to the core universes, like Underswap and Storyshift. Everything could fall. All AU's, including this timeline, and Error would win. We must stop him!" Core urged.

Ink looked grim, then he looked confused. "Wait, if he takes out the core universes, and all of the AU's are destroyed, wouldn't it destroy him, too?"

Core nodded. "But that isn't Error's task. He wants to wipe out every AU in the multiverse, which, of course, includes himself. He wishes to 'purify' the multiverse. But this cannot happen," Core said, sounding determined. "Now, you must go stop him. You're the only one who matches Error's power exactly, who will actually help in the effort. Now hurry!"

As Ink created a swirling portal of multicolored ink to the space outside the Underfell universe, Core decided to say one last thing. "Remember, Ink, you're the only one who can really defeat Error. Please, do your best."

Ink smiled kindly. "You can bet that I will, Core. And don't worry, I _will_ stop Error. I'll see you later." He stepped through the portal, and it collapsed in on itself as he passed the borders.

He would never step foot in the Omega Timeline again.


	4. The Fated Battle

**Hey guys! I'm sorry for not updating pretty much all this week. I've been super busy, doing all sorts of stuff. I haven't had any time do work on my story at all. But, now, I'm working on it again, and I hope I'll be able to update more quickly. Anyway, I left you guys on a bit of a cliffhanger last time, so let's get right into it!**

Ink paused before the colorful, swirling ink portal. Eyes narrowed in determination, he stepped through, sending ink flying out in front of him. He stopped a moment, and looked back, trying to see Core, but was too late, as the ink portal collapsed in front of him. He stared at where it had been, and for a moment, felt nervous—scared, even. But the feeling soon left him. He was on a mission, a mission that could decide the fate of the multiverse. Such a task had never been set on his shoulders before. He had faced Error before, deciding the fate of multiple universes in the past. But nothing this drastic. Though, in the midst of all this anxiety, he clutched at the large brush behind his back, and felt a rush of energy surge through him. Yes, he had faced Error before—and this time would be no different. He would stop Error, and bring peace back to the multiverse—for a time, at least. The brush soothed his worries. He was powerful, he could do this, and he would do this. For the sake of the multiverse.

He was currently floating in inter-dimensional space, between universes. Ahead of him were the core universes. They resembled massive spheres, with the events of each timeline playing out, which could be viewed from the outside. Underfell, Underswap, Storyshift, the Disbelief Universe, and Glitchtale. All of these universes imperative to the stability to the multiverse. Only a madman would attempt to infiltrate and destroy them. Not only were they the foundation of the multiverse, they surrounded and protected the most important universe of them all, the Genesis universe—Undertale. But the core universes were nearly impossible to attack and destroy themselves, so only a being of incredible power would be able to destroy them. Not many could do this, but Core and Ink both knew that Error had the power to accomplish such a feat.

Gripping the brush and pulling it off his back, Ink used it to create a trail in front of him to traverse the white void. Walking for a while, he eventually came to the universal sphere that contained the Underfell universe, and was horrified. On one side of the sphere was a still-steaming hole, rimmed around the edges dark scorch marks, and the edges of the sphere curved inward. Error had already infiltrated Underfell.

Swearing under his breath, Ink leapt off the ink trail he had created and dived into the hole. The scene around him instantly changed from that of a white sheet to that of a dark cavern, indicating he was now in the Underground of Underfell. He was still hurtling through the air, and saw snow-covered trees and a town beneath him. Ink pointed his brush ahead of himself, and continuously created an ink trail in front of himself, gliding down the ground softly instead of hitting the snow at terminal velocity.

Ink looked around anxiously, searching for signs of signs of life. He had landed in Snowdin, except it wasn't how it was in most universes. The shops were painted pure black, and the hotel looked battle-scarred and worn. Placing his brush back on his back, Ink walked slowly through the town, calling out to those who might be alive.

"Hello?" Ink called, his voice resounding through the town. No answer. "Hello? Is anyone there? If anyone is here, please answer!" Nothing.

As he walked, he stepped on something. Ink leaned down, and pulled a large, black and red scarf from underneath his foot. Near it lay a rather intimidating spiked battle body, nearly completely black. It was Papyrus.

Ink stepped up, shaking his head. "No, no, no...I—I couldn't have been late…"

"Well, I'm afraid that you were," a distorted, dark voice came from behind him. Ink spun around, and found himself facing none other than Error. He grinned maniacally. "Oh, come on, Ink…you know that you've missed me. How's the wife? How's the kids?" Ink said nothing.

Error truly looked like a madman at that point. His dark coat was covered in white monster dust. Though, not a scratch was on him. The inhabitants of Underfell hadn't stood a chance. The blue strings leading down from his eyes to the bottom of his face were clearer than ever. A few blue strings were still trailing off of his fingers, showing that he had used them on someone.

Ink then scowled. "Error…I don't think you understand what you've just done."

"Then please…educate me on my wrongdoings," Error smirked, indicating himself sarcastically. "I'm definitely feeling sorry for all of my sins."

"Error, you've just destroyed one of the core universes!" Ink cried, looking angry as ever. The star in one of his eyes flared up. "This won't be like one of our other fights in the past. Error, I'm going to have to kill you, once and for all."

Error gave him a blank stare, then laughed out loud. It was actually slightly disturbing, with his voice stopping and starting, changing pitched, distorted and strange. He turned back to Ink after stopping, a yellow smile on his face. "You… _kill_ me? Don't make me laugh. Or do. Whatever," he added, not amusing Ink in the slightest. "You're _never_ going to able to kill me. Even with all of your power, there's absolutely no way. Don't you understand, after all this time?" Ink's expression didn't change. "Alright. Let me explain," Error said slowly, smirking. "I destroy, and you create. Two sides of the coin, Yin and Yang, whatever you want to call it. When one exists, so does the other." Ink narrowed his eyes. "There either has to be both of us, or neither of us. _We cannot destroy each other_."

Ink's eyes widened. "No…that's wrong. One of us has to be stronger, there has to be an end." He looked down at the snow on the ground. "There has to."

"No," Error said coldly. "There _is_ no end. And your 'Core' buddy knew that. Why do you think they only sent you to stop me?" Error questioned. "Because they knew you could balance my power, they knew that you could 'neutralize' me. They don't want you to ever win—they want the balance to continue…they want us to suffer."

Ink looked up, and narrowed his eyes. "Well, if they think the balance should continue…then it should. And…" Ink mentioned, smiling. "There's something else. Something that I feel will break the cycle. Something big is coming Error."

Error smirked menacingly. "Oh? And what's that? Some magical thing that could stop me?"

Ink shook his head. "No. Seven words." Error looked confused. "Seven words, repeating themselves over and over throughout the multiverse. Seven words, over and over, in the mind of every living thing in all universes." Ink explained, his words getting faster and faster. "Core told me. They're everywhere at once, and so they've heard it an unimaginable amount of times. Though, it seems no one knows what the words are except them." Ink nodded. "These words are signaling a change, Error. It could mean that…maybe we could lay down our tasks." Error stared at him attentively. "It could mean that I wouldn't have to always create, and…you wouldn't always have to destroy." Ink softly smiled.

Error stared at him, face morphing into that of fury. "Tasks?" He said softly. " _Tasks?_ I've taken this job onto myself, destroying all of the dirty glitches of the multiverse, cleaning up the filth, cleansing all of reality." He was angry now, and was no longer smiling. "It's a thankless job, but I do it anyway. I leave _none—"_ He stopped. He looked at Ink. "I leave none alive."

Ink looked at him sadly. "Well…I was really hoping to get you to stop all this. Maybe today would be the day." He glanced down at the snow on the ground, then at the snow-covered trees around them. "But, I guess we'll really have to do this, then." He looked directly at Error. "No holding back, because I sure won't."

Then, for the first time in what seemed like forever, Ink activated the magic in his star eye. It glowed a light blue color, floating into the air and dissipating. He stared at Error, whose eyes were wide with…excitement? Fear? It was hard to tell.

Then he smiled. "Heh…well, since I lost that ability to do that a long time ago…" Error began. "I guess I'll just—"

Suddenly, a huge black and red Gaster Blaster glitched into reality feet away from Ink's face, and fired, shooting a massive stream of energy, "ERROR" messages surrounding it. Not truly expecting a quick victory, Error simply looked up, and saw Ink, sitting on a platform of ink, having escaped the blast. Error smirked, then teleported in his face, dodged a quick swing of a giant brush, and sent a swarm of black bones at Ink. He dodged, and teleported to the other side of Snowdin, attempting to assess the situation. So this was it. This was going to be their final battle. Ink smiled. This was going to be a lot of fun.

Error then teleported in front of Ink, swinging three dark bones in front of him using magic, approaching Ink at a leisurely pace, and smirking. Ink whipped out his brush, and swung it in front of himself, blocking the occasional bone thrown his way while simultaneously blocking the rapidly approaching Error. Deciding to take control of the situation, Ink teleported behind Error, in the air, and summoned a horde of Gaster Blasters of his own. They were white, with ink splatters along the sides. When they fired, streams of multicolored ink shot from the mouths, which hurtled towards Error's back. Noticing he was gone, Error spun around, quickly summoning a wall of bones from the ground to protect him from the oncoming ink blasts. When they collided, Error stumbled back, feeling the force of the impact on himself as well as the wall of bones.

"Now… _this is fun!_ " Error yelled with glee. He looked towards Ink and, with a wave of his arm, summoned a group of his own distorted Gaster Blasters. They fired, pushing back the wave of ink until they were balanced at the center. The two Sanses were pushing their hardest to overcome the other, but neither one could really overcome the other. Then they both thought of an idea. Using his free hand, Error shot his hand out, shooting blue strings of pure magic out of his fingers towards a nearby tree. They wrapped themselves around it and, with a wave of his hand, de-rooted the tree and launched it at Ink. At the same time, Ink swung his huge brush around his head, generating magical energy. He then poked around the edge of the Gaster Blasters, pointed the bristles at Error, and shot a blast of condensed magical energy.

The sphere of energy and the tree intersected and exploded with massive force that blue both groups of Gaster Blasters away, also throwing Ink and Error into the snow. Ink, having been knocked out of the air, took longer to recover than Error. While Ink was attempting to free himself from the snow, he looked up and saw a wave of blue strings approaching him. They moved too fast for him to react, and soon found himself being brought into the air.

Error, standing beneath him, hand controlling the strings, smirked. "What's wrong, Ink? You're looking a little…" he brought his arm behind him. " _Tied up!"_ He said as through his arm across his body. The strings flew Ink through the air, over the beaten up hotel. Then, as Ink reached the maximum height of his fall, Error summoned an inescapable sphere of dark Gaster Blasters around him. Ink's eyes widened. As quickly as possible, Error poured his magic into the Gaster Blasters and fired. They created what seemed like a firework of destructive energy, extending over the length of the barren Snowdin. Firing into the woods, snow, and shops. It was truly a terrifying sight, light shining over the Underground. Even though it was so destructive, Error still knew he had not been victorious yet. When the dragon skulls dissipated, what was left was a protective sphere of ink. Having conjured it at the last second, Ink had barely survived the devastating attack. Creating such a powerful ink shell had tired him, and he didn't know how much longer he could go. But, he had one trick up his sleeve. One more strategy that could take down Error. Ink knew it would be risky—but he felt it was the only way. Ink was determined.

"Come on down, lazy!" Error yelled at the sphere hovering over the hotel. "I know you're in there. What was it you said before about 'not holding back'?"

He was about to get more than he reckoned for. Because, inside the sphere, a change was happening. Ink closed his eyes, and concentrated. He thought about why he was here, what he was doing, and why he had to do it. He thought about all he had created, and all he sought to keep alive. He thought of the other side of the coin, Error, and why he had to stop him. He was ready. Ink held the brush in his hands, and began pulling it into himself. Long ago, Ink had infused most of his magical ability into the brush. Now, he was returning it to himself.

Error was at his wits end. Hands on his hips, he was about to kill Ink right here and now. Suddenly, the ink sphere exploded. Shattered pieces rained down from the sky, leaving one figure in the middle of it all. It was Ink. Except now he was transformed. The jacket he once wore around his waist was now being worn. His scarf covered his mouth. His shoes now indefinitely leaked ink, as did his shirt and scarf. His eyes were now both yellow stars, and both of his eyes were now emitting a light blue magic aura.

Error stared at Ink, eyes wide. "Well then…" he said slowly. "I guess your _brush_ with death went better than expec—"He didn't finish his statement, as Ink had suddenly lobbed a condensed magic ink sphere at Error.

He barely teleported out of the way, and looked at Ink in a fury. Ink was smiling now. Error narrowed his eyes. "Alright…fine. I'll give it my all. But, I have to warn you…" he summoned a squadron of Gaster Blasters and what seemed like a forest of dark bones behind him. "I have a slight _ink_ ling that this is the end."

The battle that then ensued was extraordinary. Bones flew, Beams of energy shot through the air, globs of paint were shot, strings were thrown, and all the while Error was laughing. He summoned a wave of bones that headed towards Ink, as well as conjuring a line of Gaster Blasters behind him. Ink simply jumped high into the air, spun around, and shot a wave of destructive ink at the line of Gaster Blasters. Ink then teleported around Error rapidly, shooting globs of paint at him from all directions. Error shot strings from his fingers, quickly wrapping them around the globs and flung them back at their creator.

This continued, until Ink teleported in front of Error. He then used much of his magic to conjure a massive Gaster Blaster in front of him. Error, eyes widening, set up as many layers of bones as he could between himself and the dragon skull. But the blast never came. Instead of shooting the blaster, Ink himself leapt forwards. He launched himself into the air, coming down onto Error himself, a sphere of ink in his hand, ready to strike and kill Error with. Noticing the Gaster Blaster hadn't fired, Error looked up. He saw Ink descending on top of him, rapidly coming down on top of him. His eyes widened. He only had time to create one layer of bones before Ink thrust the sphere into the wall of bones, creating a massive explosion that threw Error clear across the length of Snowdin, landing hard into the snow and rolling much farther.

The bones Error had created dissipated. All signs of battle stopped. Snowdin was still. Even in his ascended state of power, the battle had worn Ink out. He breathed heavily as he trudged through the snow to where Error had landed. When he arrived at a large hole in the snow, he looked down, Error laying at the bottom of it. He had a blank stare on his face, as he stared upwards, seemingly searching for the top of the cavern. But he was still conscious, just as tired as Ink was.

Ink smiled. "Well, Error…I guess I finally won. But, you know that this doesn't have to the end. I can get you out of here, take you to a world you can't escape, and you can live there." Ink looked down at him. Error said nothing. "Error, I've won. It's over. It's the end. I've stopped you. Just come on, don't make me kill you."

Error finally recognized him, and looked up at Ink. "This isn't the end," he said in a deep, hoarse voice that seemed even more distorted than normal."

Ink dropped down into the hole, grabbed onto Error's arm, and teleported him back onto the ground. He looked up and down at Error. "You're right. This _isn't_ the end. Because, you're not going to destroy universes anymore. You're going to live in peace from now on. Come on." Ink said, smiling kindly, hoping optimistically that that Error would come peacefully.

Error smiled. But it wasn't a smile of goodwill or peace. It was a smile of a madman, of someone who still wanted to murder and commit genocide again. Ink took a step back, horrified, terrified, and afraid. Error's eyes seemed to shift and change in front of him, and the "ERROR" messaged around him seemed to multiply.

Error giggled maniacally. " ** _This isn't the end._** "

Suddenly, Ink's eyes widened, and a large kind of butcher's knife suddenly sprouted from his stomach. His pupils dilated, and his skeleton smile shrunk. He looked down slowly, and saw the knife, ripped through his jacket. Ink choked, and looked up at Error. He still had that insane smile on his face. The knife was ripped back out of Ink's back, and he wobbled unsteadily on the spot. He then tipped backwards, falling into the snow. Blood stained his jacket, and his vision started to blur. Ink looked up from his spot on the ground, and saw two figures. The new figure looked just as maniacal as Error. He stood on the right…or was it the left? It didn't matter now. His eye glowed purple, and he wore the traditional blue Sans jacket. Except that his hood was over his head, and the jacket was absolutely coated in white monster dust. The two stood above Ink, still smiling.

Ink coughed up blood on his jacket. "Error…" he said weakly. "W-Why…who is…why would you…"

Error shushed him. "You were right, Ink…huge things are coming. The only thing different is that you're not included." He finally stopped smiling for a moment. "Ink…I don't know how this will work, with you gone. The whole yin-yang thing. But, I just want to say one thing…" Error leaned down, and said one last thing to Ink. "I _will_ miss you, though." He then conjured a spiked bone into his hand, and thrust it forward.

Dust. A brush on the ground. The remains of the fallen creator. Error picked up the brush, and grinned. " _This,_ " he said, nodding to his companion. "Will be very, very useful." He turned away, and started walking through Snowdin. "Come on," he said, smirking. "I think there may be a few inhabitants left. And I want to test my new toy."


End file.
